I have invented a somewhat similar cutter device for thermoplastic material which is described in U.S. Pat. No. 3,180,195, issued Apr. 27, 1965. However, the cutter device of this instant application differs in considerable detail from the device described in the prior patent. For example, one important distinction is the manner in which guide means for the knife blade are arranged in this device to more efficiently, more accurately, and more controllably direct the movement of the knife blade than was provided by the knife blade guide means of my prior patent. I found that the guide means employed in my prior patent occasionally had a tendency to bind because of the geometric arrangement of the guide means in relation to the body frame and knife blade of the cutting device. In this application I have disposed the guide means for the knife blade in a manner that a flat side of the guide means moves slidably against a substantial flat side of the body frame thus eliminating the tendency to bind. By "binding," I mean that the knife blade would become canted in its movement down the frame and have a tendency to become stuck so that further easy movement was difficult. The present guide means causes the knife blade to remain in the same proper horizontal disposition during its downward and upward movement in the frame. Another distinction that I have made in this present invention is to provide a double edged knife blade, whereas the prior patent concerned only a single edged blade which was effective only in the downward cutting movement. The present blade provides a cutting motion both downward and upward.
Another important distinction I have made in the present invention compared to my prior patent is to provide a simpler and more efficient means of pushing the thermoplastic article along the support frame of the device. In the prior patent I positioned a horizontal piston rod and cylinder on each side of the frame to move the reciprocable plunger horizontally along the cylindrical chamber of the device. I have found that the device is simpler and more efficient in operation by providing a single piston rod and cylinder behind the plunger member in axial alignment therewith to force the horizontal movement of the reciprocable plunger and consequently the article of thermoplastic material. In addition to the distinctions described above, I have provided numerous other improvements in a cutter device which will be described in detail hereinafter.
The principle object of this invention is to provide a cutter device for thermoplastic materials which is simple in construction, easy and efficient to operate, and inexpensive to manufacture.
Another object of this invention is to provide a cutter device for thermoplastic material which has a high capacity for cutting articles of thermoplastic material into smaller portions, efficiently and quickly and with great ease in handling and moving the thermoplastic material.
Still another object of this invention is to provide means for handling articles of thermoplastic material which are simple in construction, easy to maintain, and easy to operate.